Polar code encoding method and device

ABSTRACT

Disclosed in embodiments of the present disclosure are a polar code encoding method and device. The method includes: utilizing a common information bit set to represent each of m polar code blocks, the polar codes in each polar code block having the same code length and different code rates, and m being greater than or equal to 2; according to the common information bit set corresponding to the polar code block, acquiring an information bit set corresponding to each polar code in the polar code block; and according to the information bit set corresponding to each polar code in the polar code block, conducting polar code encoding on information to be encoded, thus reducing polar code representation overhead, and solving the problem in the prior art of excessively high polar code representation overhead.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/151,320, filed on May 10, 2016, which is a continuation of International Patent Application No. PCT/CN2013/086871, filed on Nov. 11, 2013. All of the afore-mentioned patent applications are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the field of communication, and particularly to a polar code encoding method and device.

BACKGROUND

In a communication system, channel encoding is generally used to improve reliability of data transmission and ensure communication quality. A Polar code is a good code which can achieve Shannon capacity by theoretical proof and has a low encoding and decoding complexity. If the code length is short, the performance of conventional successive cancellation (SC) decoding is worse than performances of a low density parity check (LDPC) code and a Turbo Code. In a case of decoding with list codes, the performance of the Polar code with medium code length is better than performances of the LDPC code or the Turbo Code.

The Polar code is a linear block code, and the generator matrix thereof is G_(N). The process of Polar code encoding is x₁ ^(N)=u₁ ^(N)G_(N), where x₁ ^(N) is an output bit after encoding, u₁ ^(N) is an input bit before encoding, G_(N)=B_(N)F^(⊗) ^(n) . The code length N=2^(n), and n≥0. B_(N) is a transposed matrix such as a bit reversal matrix. F^(⊗n) is a Kronecker power (Kronecker power) of F, which is defined as F^(⊗n)=F⊗F^(⊗n) ⁻¹ , where

$F = {\begin{bmatrix} 1 & 0 \\ 1 & 1 \end{bmatrix}.}$

The Polar code may be represented as (N, K, A, u_(A) _(c) ) with a coset code, and the encoding process is x₁ ^(N)=u_(A)G_(A)(A)⊕u_(A) _(c) G_(N)(A^(c)). A is an information bit index set G_(N)(A) is a submatrix obtained from a row, which corresponds to the index in the set A, in G_(N). G_(N) (A^(c)) is a submatrix obtained from a row, which corresponds to the index in the set A^(c), in G_(N). u_(A) _(c) is Frozen bits the number of which is (N−K), with N being the code length and K being the length of information bits. For simplicity, the Frozen bit may be set to 0, and in this case, the above encoding process is briefly described as x₁ ^(N)=u_(A)G_(N) (A).

In the conventional technology, a Polar code with a code length being N and a code rate being R₁ is represented as (N, K₁, A₁), a second Polar code with a code length being N and a code rate being R₂ is represented as (N, K₂, A₂), and a Polar code with a code length being N and a code rate being R₃ is represented as (N, K₃, A₃). Polar codes with a same code length and different code rates are represented differently. For example, a first Polar code with the code length being 2048 and the number of information bits being 683 is represented as (2048, 683, A₁), where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}. A second Polar code with the code length being 2048 and the number of information bits being 1024 is represented as (2048, 1024, A₂), where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}. A₁ and A₂ include a large number of same elements. However, in the conventional technology, the first Polar code and the second Polar code need to be represented by A₁ and A₂ respectively, which causes a high overhead for representing the Polar code conventionally.

SUMMARY

A method and an apparatus for Polar code encoding are provided according to embodiments of the disclosure, in which encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, and the overhead for representing the Polar codes is greatly reduced.

To achieve the above object, technical solutions adopted in the embodiments of the disclosure are as follows.

In a first aspect, a method for Polar code encoding is provided. The method includes:

representing each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtaining an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

performing Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the first aspect, according to the first aspect, information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the first aspect, according to the first aspect or the first possible implementation of the first aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a second aspect, a method for Polar code encoding is provided. The method includes:

representing each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtaining a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

performing Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the second aspect, in conjunction with the second aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the second aspect, in conjunction with the second aspect or the first possible implementation of the second aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In a third aspect, an apparatus for Polar code encoding is provided, which includes:

a representing unit configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

an obtaining unit configured to obtain an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

an encoding unit configured to perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the third aspect, in conjunction with the third aspect,

information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the third aspect, in conjunction with the third aspect or the first possible implementation of the third aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a fourth aspect, an apparatus for Polar code encoding is provided, which includes:

a processor configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the fourth aspect, in conjunction with the fourth aspect,

information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the fourth aspect, in conjunction with the fourth aspect or the first possible implementation of the fourth aspect, the common information bit set corresponding to the Polar code group is a union of information bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is an information bit set corresponding to a Polar code with any code rate in the Polar code group.

In a fifth aspect, an apparatus for Polar code encoding is provided, which includes:

a representing unit configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

an obtaining unit configured to obtain an information bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

an encoding unit configured to perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the fifth aspect, in conjunction with the fifth aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the fifth aspect, in conjunction with the fifth aspect or the first possible implementation of the fifth aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In a sixth aspect, an apparatus for Polar code encoding is provided, which includes:

a processor configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

In a first possible implementation of the sixth aspect, in conjunction with the sixth aspect, Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element.

In a second possible implementation of the sixth aspect, in conjunction with the sixth aspect or the first possible implementation of the sixth aspect, the common Frozen bit set corresponding to the Polar code group is a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the Polar code group, or is a Frozen bit set corresponding to a Polar code with any code rate in the Polar code group.

In the methods and apparatuses for Polar code encoding according to the embodiments of the disclosure, each Polar code group in the m Polar code groups is represented by a common information bit set or a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; an information bit set or a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set or the common Frozen bit set corresponding to the Polar code group, and Polar code encoding is performed on information to be encoded based on the information bit set or the Frozen bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent information bit set or an independent Frozen bit set.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the technical solutions according to embodiments of the disclosure or in the conventional technology more clearly, the drawings to be used in the description of the embodiments or the conventional technology are described briefly hereinafter. Apparently, the drawings in the description are just a few embodiments of the disclosure, and other drawings may be obtained by those skilled in the art according to those drawings without creative effort.

FIG. 1 is a flow chart of a method for Polar code encoding according to an embodiment of the disclosure;

FIG. 2 is a schematic diagram of a common information bit set of each Polar code group according to an embodiment of the disclosure;

FIG. 3 is a flow chart of another method for Polar code encoding according to an embodiment of the disclosure;

FIG. 4 is a schematic diagram of an apparatus for Polar code encoding according to an embodiment of the disclosure;

FIG. 5 is a schematic diagram of another apparatus for Polar code encoding according to an embodiment of the disclosure;

FIG. 6 is a schematic diagram of another apparatus for Polar code encoding according to an embodiment of the disclosure; and

FIG. 7 is a schematic diagram of another apparatus for Polar code encoding according to an embodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions in embodiments of the disclosure will be described clearly in conjunction with drawings in the embodiments of the disclosure hereinafter. Apparently, the described embodiments are just a few rather than all of embodiments of the disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the disclosure without any creative work will fall within the protection scope of the disclosure.

It should be noted that, numbers such as 101 and 102 involved in the embodiments of the disclosure are only to identify steps of the method, and not to limit the sequence of the numbered steps.

In an aspect, a method for Polar code encoding is provided according to an embodiment of the disclosure. As shown in FIG. 1, the method may include steps 101 to 103.

In 101, each Polar code group in m Polar code groups is represented by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates and m is greater than or equal to 2.

Exemplarily, multiple Polar codes with a same code length and different code rates may be divided into m Polar code groups, each Polar code group includes one or more Polar codes with different code rates, and information bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element, where m is greater than or equal to 2.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar codes are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that information bit indexes included in the information bit sets corresponding to the Polar codes with different code rates in each group include at least one same information bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in the background, or may be determined by using other methods, and the embodiment of the disclosure is not limited therein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂ where A₂ is a subset including 1024 elements of a set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share an information bit set or a Frozen bit set assigned for the group.

For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i), and |A_(i)|=K_(si), where |A_(i)| and K_(si) represent the total number of elements in the common information bit set A_(i) of the i-th Polar code group, e.g., K_(s1) represents the total number of elements in the common information bit set A₁ of the first Polar code group, and K_(s2) represents the total number of elements in the common information bit set A₂ of the second Polar code group.

Each Polar code in any Polar code group may be represented by a common information bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N, K_(t)), where N is the code length, and K_(t) represents the first K_(t) information bit indexes of the common information bit set A_(i) of the Polar code group. Thus, compared to the conventional technology, overhead for representing Polar codes having a same code length and different code rates is saved.

Exemplarily, the common information bit set A corresponding to the i-th Polar code group may be a union of information bit sets respectively corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be an information bit set corresponding to a Polar code with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common information bit set of the i-th Polar code group may be an information bit set corresponding to a code length of 2048 and a code rate of 0.6.

Exemplarily, a recurrence relation is among common information bit sets corresponding to different Polar code groups in the m Polar code groups.

Exemplarily, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1} \\ {A_{i} = {A_{i - 1}\bigcup{\delta \; A_{i}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, and δA_(i) is a difference set between the set A_(i) and the set A_(i−1);

or,

$\left\{ {\begin{matrix} A_{i} \\ {A_{j} = {\left( {A_{i} - {\zeta \; A_{j}}} \right)\bigcup{\delta \; A_{j}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, the set A_(j) is a common information bit set corresponding to a j-th Polar code group, ζA_(j), is a difference set between the set A_(i) and the set A_(j), and i is not equal to j.

Referring to FIG. 2, A₁ includes elements of K₁, K₂, . . . , K_(s1), A₂ includes elements of K_(s1+1), K_(s1+2), . . . , K_(s1+s2), and A_(m) includes elements of K_(sm−1+1), K_(sm−1+2), . . . , K_(sm−1+sm), where a recurrence relation is among A₁, A₂, . . . , A_(m).

For example, the code length N=16, and A₁, A₂, A₃ correspond to common information bit sets of three Polar code groups respectively,

A1={16, 15, 14, 12, 9},

A2={16, 15, 14, 12, 8, 13, 11, 10},

A3={16, 15, 14, 12, 9, 13, 11, 10, 7, 6, 4},

δA₂={8, 13, 11, 10},

ζA₂={9},

δA₃={9, 7, 6, 4},

ζA₃={8}.

In 102, an information bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set corresponding to the Polar code group.

In a case that Polar codes in each Polar code group share a common information bit set assigned for the group, the information bit set corresponding to any Polar code (N, K_(t)) in the i-th Polar code group includes the first K_(t) information bit indexes of the common information bit set A_(i) of the Polar code group represented by K_(t).

In 103, Polar code encoding is performed on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

Exemplarily, if the number of bits of the information to be encoded is K, there is a Polar code with a certain code length and a certain code rate that corresponds to the bits of the information to be encoded, then the information to be encoded is encoded; if the bits of the information to be encoded are changed, there is a Polar code with another code length and another code rate that corresponds to the changed bits of information to be encoded, then the changed information to be encoded may be encoded.

In the method for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; an information bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set corresponding to the Polar code group, and Polar code encoding is performed on the information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent information bit set.

In another aspect, another method for Polar code encoding is provided according to an embodiment of the disclosure. As shown in FIG. 3, the method may include steps 301 to 303.

In 301, each Polar code group in m Polar code groups is represented by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2.

Exemplarily, multiple Polar codes with a same code length and different code rates may be divided into m Polar code groups, each Polar code group includes one or more Polar codes with different code rates, and Frozen bit sets respectively corresponding to all Polar codes with different code rates in each Polar code group include at least one same element, where m is greater than or equal to 2.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar codes are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that Frozen bit indexes included in the Frozen bit sets corresponding to the Polar codes with different code rates in each Polar code group include at least one same Frozen bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in background, or may be determined by using other methods, and the embodiment of the disclosure is not limited herein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂, where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share a Frozen bit set assigned for the group. For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i) ^(c), and |A_(i) ^(c)|=K_(si), where A|_(i) ^(c)| and K_(si) represent the total number of elements in the common Frozen bit set A_(i) ^(c) of the i-th Polar code group.

Each Polar code may be represented based on a common Frozen bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N, K_(t)), where N is the code length, and K_(t) represents the first (N−K_(t)) Frozen bit indexes of the common Frozen bit set A_(i) ^(c) of the group included in the Frozen bit set corresponding to the Polar code. The information bit set A is complementary to the Frozen bit set A^(c).

The common Frozen bit set A_(i) ^(c) corresponding to the i-th Polar code group may be a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be a Frozen bit set corresponding to a Polar code with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common Frozen bit set corresponding to the first Polar code group may be a Frozen bit set corresponding to a code length of 2048 and a code rate of 0.4.

A recurrence relation is among common Frozen bit sets corresponding to the m Polar code groups.

For example, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1}^{c} \\ {A_{i}^{c} = {A_{i - 1}^{c}\bigcup{\delta \; A_{i}^{c}}}} \end{matrix}\;,} \right.$

where A_(i) ^(c) is the common Frozen bit set corresponding to the i-th Polar code group, and δA_(i) ^(c) is a difference set between A_(i) ^(c) and A_(i−1) ^(c);

or,

$\left\{ {\begin{matrix} A_{i}^{c} \\ {A_{j}^{c} = {\left( {A_{i}^{c} - {\zeta \; A_{j}^{c}}} \right)\bigcup{\delta \; A_{j}^{c}}}} \end{matrix},} \right.$

where A_(i) ^(c) is a common Frozen bit set corresponding to the i-th Polar code group, A_(j) ^(c) is a common Frozen bit set corresponding to a j-th Polar code group, δA_(j) ^(c) is a difference set between the set A_(i) ^(c) and the set A_(j) ^(c), and i is not equal to j.

In 302, a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common Frozen bit set corresponding to the Polar code group.

In a case that the Polar codes in each Polar code group share a common Frozen bit set assigned for the group, the Frozen bit set corresponding to any Polar code (N, K_(t)) in the i-th Polar code group includes the first (N−K_(t)) Frozen bit indexes of the common Frozen bit set A_(i) ^(c) of the group.

In 303, Polar code encoding is performed on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

Exemplarily, if the number of bits of the information to be encoded is K, there is a Polar code with a certain code length and a certain code rate that corresponds to the bits of the information, then the information to be encoded is encoded; if the bits of the information to be encoded is changed, there is a Polar code with another code length and another code rate that corresponds to the changed bits of information to be encoded, then the changed information to be encoded may be encoded.

In the method for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common Frozen bit set, where the Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common Frozen bit set corresponding to the Polar code group, and Polar code encoding is performed on the information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent Frozen bit set.

In an aspect, an apparatus 40 for Polar code encoding is provided according to an embodiment of the disclosure. The apparatus 40 for Polar code encoding may be an independent apparatus, or may be located in an indoor baseband processing unit in a base station. Referring to FIG. 4, the apparatus 40 for Polar code encoding includes a representing unit 401, an obtaining unit 402, and an encoding unit 403.

The representing unit 401 is configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar codes are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that information bit indexes included in the information bit sets corresponding to the Polar codes with different code rates in each group include at least one same information bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in background, or may be determined by using other methods, and the embodiment of the disclosure is not limited therein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂, where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share an information bit set or a Frozen bit set assigned for the group.

For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i), and |A_(i)|=K_(si), where |A_(i)| and K_(si) represent the total number of elements in the common information bit set A_(i) of the i-th Polar code group, e.g., K_(s1) represents the total number of elements in the common information bit set A₁ of the first Polar code group, and K_(s2) represents the total number of elements in the common information bit set A₂ of the second Polar code group.

Each Polar code in any Polar code group may be represented by a common information bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N, K_(t)), where N is the code length, and K_(t) represents the first K_(t) information bit indexes of the common information bit set A_(i) of the Polar code group. Thus, compared with the conventional technology, overhead for representing the Polar codes with a same code length and different code rates is saved.

Exemplarily, the common information bit set A corresponding to the i-th Polar code group may be a union of information bit sets respectively corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be an information bit set corresponding to a Polar code with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common information bit set of the i-th Polar code group may be an information bit set corresponding to a code length of 2048 and a code rate of 0.6.

Exemplarily, a recurrence relation is among common information bit sets corresponding to different Polar code groups in the m Polar code groups.

Exemplarily, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1} \\ {A_{i} = {A_{i - 1}\bigcup{\delta \; A_{i}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, and δA_(i) is a difference set between the set A_(i) and the set A_(i−1);

or,

$\left\{ {\begin{matrix} A_{i} \\ {A_{j} = {\left( {A_{i} - {\zeta \; A_{j}}} \right)\bigcup{\delta \; A_{j}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, the set A_(j) is a common information bit set corresponding to a j-th Polar code group, ζA_(j) is a difference set between the set A_(i) and the set A_(j), and i is not equal to j.

Referring to FIG. 2, A₁ includes elements of K₁, K₂, . . . , K_(s1), A₂ includes elements of K_(s1+1), K_(s1+2), . . . , K_(s1+s2), and A_(m) includes elements of K_(sm−1+1), K_(sm−1+2), . . . , K_(sm−1+sm), where a recurrence relation is among A₁, A₂, . . . , A_(m).

For example, the code length N=16, and A₁, A₂, A₃ correspond to common information bit sets of three Polar code groups respectively,

A1={16, 15, 14, 12, 9},

A2={16, 15, 14, 12, 8, 13, 11, 10},

A3={16, 15, 14, 12, 9, 13, 11, 10, 7, 6, 4},

δA₂={8, 13, 11, 10},

ζA₂={9},

δA₃={9, 7, 6, 4},

ζA₃={8}.

The obtaining unit 402 is configured to obtain an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group.

In a case that the Polar codes in each Polar code group share a common information bit set assigned for the group, the information bit set corresponding to any Polar code (N, K_(t)) in the i-th Polar code group includes the first K_(t) information bit indexes of the common information bit set A_(i) of the Polar code group represented by K_(t).

The encoding unit 403 is configured to perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

Exemplarily, if the number of bits of the information to be encoded is K, there is a Polar code with a certain code length and a certain code rate that corresponds to the bit of information to be encoded, and then the information to be encoded is encoded; if bits of the information to be encoded is changed, there is a Polar code with another code length and another code rate that corresponds to the changed bits of information to be encoded, and then the changed information to be encoded may be encoded.

In the apparatus 40 for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common information bit set, where the Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; an information bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set corresponding to the Polar code group, and Polar code encoding is performed on the information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent information bit set.

In an aspect, another apparatus 50 for Polar code encoding is provided according to an embodiment of the disclosure. Referring to FIG. 5, the apparatus 50 for Polar code encoding includes a storage 501 and a processor 502.

The storage 501 is configured to store Polar codes.

The processor 502 is configured to represent each Polar code group in m Polar code groups by a common information bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain an information bit set corresponding to each Polar code in the Polar code group based on the common information bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar codes are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that information bit indexes included in the information bit sets corresponding to the Polar codes with different code rates in each group include at least one same information bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in background, or may be determined by using other methods, and the embodiment of the disclosure is not limited herein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂, where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share an information bit set or a Frozen bit set assigned for the group.

For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i), and |A_(i)|=K_(si), where |A_(i)| and K_(si) represent the total number of elements in the common information bit set A_(i) of the i-th Polar code group, e.g., K_(s1) represents the total number of elements in the common information bit set A₁ of the first Polar code group, and K_(s2) represents the total number of elements in the common information bit set A₂ of the second Polar code group.

Each Polar code in any Polar code group may be represented by a common information bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N, K_(t)), where N is the code length, and K_(t) represents the first K_(t) information bit indexes of the common information bit set A_(i) of the Polar code group. Thus, compared to the conventional technology, overhead for representing Polar codes with a same code length and different code rates is saved.

Exemplarily, the common information bit set A corresponding to the i-th Polar code group may be a union of information bit sets respectively corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be an information bit set corresponding to a Polar code with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common information bit set of the i-th Polar code group may be an information bit set corresponding to a code length of 2048 and a code rate of 0.6.

Exemplarily, a recurrence relation is among common information bit sets corresponding to different Polar code groups in the m Polar code groups.

Exemplarily, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1} \\ {A_{i} = {A_{i - 1}\bigcup{\delta \; A_{i}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, and δA_(i) is a difference set between the set A_(i) and the set A_(i−1);

or,

$\left\{ {\begin{matrix} A_{i} \\ {A_{j} = {\left( {A_{i} - {\zeta \; A_{j}}} \right)\bigcup{\delta \; A_{j}}}} \end{matrix},} \right.$

where the set A_(i) is a common information bit set corresponding to the i-th Polar code group, the set A_(j) is a common information bit set corresponding to a j-th Polar code group, ζA_(j) is a difference set between the set A_(i) and the set A_(j), and i is not equal to j.

Referring to FIG. 2, A₁ includes elements of K₁, K₂, . . . , K_(s1), A₂ includes elements of K_(s1+1), K_(s1+2), . . . , K_(s1+s2), and A_(m) includes elements of K_(sm−1+1), K_(sm−1+2), . . . , K_(sm−1+sm), where a recurrence relation is among A₁, A₂, . . . , A_(m).

For example, the code length N=16, and A₁, A₂, A₃ correspond to common information bit sets of three Polar code groups respectively,

A1={16, 15, 14, 12, 9},

A2={16, 15, 14, 12, 8, 13, 11, 10},

A3={16, 15, 14, 12, 9, 13, 11, 10, 7, 6, 4},

δA₂={8, 13, 11, 10},

ζA₂={9},

δA₃={9, 7, 6, 4},

ζA₃={8}.

In the apparatus 50 for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common information bit set, where the Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; an information bit set corresponding to each Polar code in the Polar code group is obtained based on the common information bit set corresponding to the Polar code group, and Polar code encoding is performed on information to be encoded based on the information bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent information bit set.

In an aspect, an apparatus 60 for Polar code encoding is provided according to an embodiment of the disclosure. The apparatus 60 for Polar code encoding may be an independent apparatus, or may be located in an indoor baseband processing unit in a base station. Referring to FIG. 6, the apparatus 60 for Polar code encoding includes a representing unit 601, an obtaining unit 602, and an encoding unit 603.

The representing unit 601 is configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar code are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that Frozen bit indexes included in the Frozen bit sets corresponding to the Polar codes with different code rates in each group include at least one same Frozen bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in background, or may be determined by using other methods, and the embodiment of the disclosure is not limited herein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂, where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share a Frozen bit set assigned for the group. For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i) ^(c), and |A_(i) ^(c)|=K_(si), where A|_(i) ^(c)| and K_(si) represent the total number of elements in the common Frozen bit set A_(i) ^(c) of the i-th Polar code group.

Each Polar code may be represented based on a common Frozen bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N, K_(t)), where N is the code length, and K_(t) represents the first (N−K_(t)) Frozen bit indexes of the common Frozen bit set A_(i) ^(c) of the group included in the Frozen bit set corresponding to the Polar code. The information bit set A is complementary to the Frozen bit set A_(c).

The common Frozen bit set A_(i) ^(c) corresponding to the i-th Polar code group may be a union of Frozen bit sets respectively corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be a Frozen bit set corresponding to a Polar code with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common Frozen bit set corresponding to the first Polar code group may be a Frozen bit set corresponding to a code length of 2048 and a code rate of 0.4.

A recurrence relation is among common Frozen bit sets respectively corresponding to the m Polar code groups.

For example, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1}^{c} \\ {A_{i}^{c} = {A_{i - 1}^{c}\bigcup{\delta \; A_{i}^{c}}}} \end{matrix},} \right.$

where A_(i) ^(c) is the common Frozen bit set corresponding to the i-th Polar code group, and δA_(i) ^(c) is a difference set between A_(i) ^(c) and A_(i−1) ^(c);

or,

$\left\{ {\begin{matrix} A_{i}^{c} \\ {A_{j}^{c} = {\left( {A_{i}^{c} - {\zeta \; A_{j}^{c}}} \right)\bigcup{\delta \; A_{j}^{c}}}} \end{matrix},} \right.$

where A_(i) ^(c)is a common Frozen bit set corresponding to the i-th Polar code group, A_(j) ^(c) is a common Frozen bit set corresponding to a j-th Polar code group, δA_(j) ^(c) is a difference set between the set A_(i) ^(c) and the set A_(j) ^(c), and i is not equal to j.

The obtaining unit 602 is configured to obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group.

In a case that the Polar codes in each Polar code group share a common Frozen bit set assigned for the group, the Frozen bit set corresponding to any Polar code (N, K_(t)) in the i-th Polar code group includes the first (N−K_(t)) Frozen bit indexes of the common Frozen bit set A_(i) ^(c) of the group.

The encoding unit 603 is configured to perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

Exemplarily, if the number of bits of the information to be encoded is K, there is a Polar code with a certain code length and a certain code rate that corresponds to the bits of information to be encoded, and then the information to be encoded is encoded; if the bits of the information to be encoded is changed, there is a Polar code with another code length and another code rate that corresponds to the changed bits of information to be encoded, and then the changed information to be encoded may be encoded.

In the apparatus 60 for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common Frozen bit set, where the Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common Frozen bit set corresponding to the Polar code group, and Polar code encoding is performed on the information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent Frozen bit set.

In an aspect, another apparatus 70 for Polar code encoding is provided according to an embodiment of the disclosure. Referring to FIG. 7, the apparatus 70 for Polar code encoding includes a storage 701 and a processor 702.

The storage 701 is configured to store Polar codes.

The processor 702 is configured to represent each Polar code group in m Polar code groups by a common Frozen bit set, where Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2;

obtain a Frozen bit set corresponding to each Polar code in the Polar code group based on the Frozen bit set corresponding to the Polar code group; and

perform Polar code encoding on information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group.

Exemplarily, the code rate of any Polar code is different from each other. In the embodiment of the disclosure, preferably, Polar codes are divided so that Polar codes with the code rates being close to each other are in a Polar code group. The Polar codes may also be divided by using other division methods, and the embodiment of the disclosure is not limited herein. It is only required that Frozen bit indexes included in the Frozen bit sets corresponding to the Polar codes with different code rates in each group include at least one same Frozen bit index. The information bit set corresponding to the Polar code is an information bit index set that can be used by the Polar code, which may be determined by using the method described in background, or may be determined by using other methods, and the embodiment of the disclosure is not limited herein. For example, an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 683 may be A₁, where A₁ is a subset including 683 elements of a set {0, 1, 2, . . . , 2047}; an information bit set corresponding to a Polar code with the code length being 2048 and the number of information bits being 1024 may be A₂, where A₂ is a subset including 1024 elements of the set {0, 1, 2, . . . , 2047}.

Exemplarily, the Polar codes in each Polar code group may share a Frozen bit set assigned for the group. For example, for an i-th Polar code group, the common information bit set assigned for the i-th Polar code group is represented by A_(i) ^(c), and |A_(i) ^(c)|=K_(si), where A|_(i) ^(c)| and K_(si) represent the total number of elements in the common Frozen bit set A_(i) ^(c) of the i-th Polar code group.

Each Polar code may be represented based on a common Frozen bit set of the group. The i-th Polar code group is taken as an example for illustration. Each Polar code in the Polar code group may be represented by (N−K_(t)) where N is the code length, and K_(t) represents the first (N−K_(t)) Frozen bit indexes of the common Frozen bit set A_(i) ^(c) of the group included in the Frozen bit set corresponding to the Polar code. The information bit set A is complementary to the Frozen bit set A_(c).

The common Frozen bit set A_(i) ^(c) corresponding to the i-th Polar code group may be a union of Frozen bit sets corresponding to all Polar codes with different code rates in the i-th Polar code group, or may be a Frozen bit set corresponding to a Polar codes with a certain code rate in the i-th Polar code group, or may be obtained by using other methods, and the embodiment of the disclosure is not limited herein. For example, if the i-th Polar code group has three Polar codes, i.e., a Polar code with a code length of 2048 and a code rate of 0.4, a Polar code with a code length of 2048 and a code rate of 0.5, and a Polar code with a code length of 2048 and a code rate of 0.6, then the common Frozen bit set corresponding to the first Polar code group may be a Frozen bit set corresponding to a code length of 2048 and a code rate of 0.4.

A recurrence relation is among common Frozen bit sets respectively corresponding to the m Polar code groups.

For example, the recurrence relation may be:

$\left\{ {\begin{matrix} A_{1}^{c} \\ {A_{i}^{c} = {A_{i - 1}^{c}\bigcup{\delta \; A_{i}^{c}}}} \end{matrix},} \right.$

where A_(i) ^(c) is a common Frozen bit set corresponding to the i-th Polar code group, and δA_(i) ^(c) is a difference set between A_(i) ^(c) and A_(i−1) ^(c);

or,

$\quad\left\{ \begin{matrix} A_{i}^{c} \\ {A_{j}^{c} = {\left( {A_{i}^{c} - {\zeta \; A_{j}^{c}}} \right)\bigcup{\delta \; A_{j}^{c}}}} \end{matrix}\; \right.$

where A_(i) ^(c) is a common Frozen bit set corresponding to the i-th Polar code group, A_(j) ^(c) is a common Frozen bit set corresponding to a j-th Polar code group, δA_(j) ^(c) is a difference set between the set A_(i) ^(c) and the set A_(j) ^(c), and i is not equal to j.

In the apparatus 70 for Polar code encoding according to the embodiment of the disclosure, each Polar code group in the m Polar code groups is represented by a common Frozen bit set, where the Polar codes in each Polar code group have a same code length and different code rates, and m is greater than or equal to 2; a Frozen bit set corresponding to each Polar code in the Polar code group is obtained based on the common Frozen bit set corresponding to the Polar code group, and Polar code encoding is performed on the information to be encoded based on the Frozen bit set corresponding to each Polar code in the Polar code group. In this way, encoding is performed according to representation of Polar codes with a same code length and different code rates based on groups, which greatly reduces the overhead for representing the Polar codes and addresses the problem of large overhead for representing the Polar codes in the conventional technology, compared with the case that each Polar code is represented by an independent Frozen bit set.

Those skilled in the art should clearly know that, for convenience and concision of description, for the operation of the systems, apparatuses and units mentioned above, one can refer to corresponding processes in the method embodiments, which is not repeated herein.

It should be understood that, in the embodiments of the disclosure, the disclosed systems, apparatuses and methods may be implemented in other ways. For example, the device embodiments described above are just exemplary. The units are divided based on logical functions, and may also be divided in other ways in practical implementation. Multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the displayed or discussed couplings, direct couplings or communication connections may be indirect couplings or communication connections through some interfaces, apparatuses or units, which may be electrical, mechanical or in other forms.

The units described as separate components may be or may not be separated physically. The components shown as units may be or may not be physical units, i.e., the units may be located at one place or may be distributed onto multiple network units. All of or part of the units may be selected based on actual needs to achieve the purposes according to the embodiments of the disclosure.

In addition, individual function units according to the embodiments of the disclosure may be integrated in one processing unit, or the units may exist separately, or two or more units may be integrated in one unit. The foregoing integrated units may be realized in a form of hardware, or realized in a form of combination of hardware and software functional units.

The integrated unit implemented in the form of software function unit may be stored in a computer readable storage medium. The software function unit mentioned above is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device or the like) to implement part of the steps of the methods according to the embodiments of the disclosure. The foregoing storage medium includes various media that can store program codes, for example, USB disk, mobile hard disk drive, read-only memory (ROM), random access memory (RAM), magnetic disk, optical disk and the like.

It should be noted that, the embodiments mentioned above are only to illustrate the technical solutions of the disclosure, rather than to limit the scope of the disclosure. Though the disclosure is described in detail according to the embodiments mentioned above, those skilled in the art should understand that, the technical solution according to the embodiments mentioned above may be modified, or some technical features may be substituted equivalently; and these modifications or substitutions do not make the essence of the corresponding technical solution depart from the spirit and scope of the technical solutions in the embodiments of the disclosure. 

What is claimed:
 1. A channel coding method, performed by a coding device in a communication system, comprising: obtaining K bits of data, wherein K is greater than or equal to 1; obtaining an information bit index set from a common bit index set, wherein the information bit index set comprises K indexes, the common bit index set comprises M indexes, and wherein M is greater than or equal to K; encoding the K bits of data using the information bit index set, to generate a polar code; and outputting the polar code; wherein polar codes generated by encoding data bits using an information bit index set obtained from the common bit index set have a same code length.
 2. The method according to claim 1, wherein the common bit index set is a union of information bit index sets corresponding to all of polar code generated by encoding data bits using an information bit index set obtained from the common bit index set.
 3. The method according to claim 1, wherein all of polar code generated by encoding data bits using an information bit index set obtained from the common bit index set corresponding to a group of polar codes, the group of polar codes has different code rates.
 4. The method according to claim 1, wherein the group of polar codes is one of m groups of polar codes, and wherein there is a recurrence relation among common bit index sets corresponding respectively to m groups of polar codes, wherein m is greater than or equal to
 2. 5. The method according to claim 4, wherein the recurrence relation among the common bit index sets corresponding respectively to the m groups of polar codes is: $\left\{ {\begin{matrix} A_{1} \\ {A_{i} = {A_{i - 1}\bigcup{\delta \; A_{i}}}} \end{matrix},} \right.$ wherein A_(i) is a common bit index set corresponding to an i-th group of polar codes, and δA_(i) is a difference set between A_(i) and A_(i−1).
 6. An apparatus for channel coding, comprising a process and a storage having processor-executable instructions stored thereon that, when executed by the processor, cause the apparatus to: obtain K bits of data, wherein K is greater than or equal to 1; obtain an information bit index set from a common bit index set, wherein the information bit index set comprises K indexes, the common bit index set comprises M indexes, and wherein M is greater than or equal to K; encode the K bits of data using the information bit index set, to generate an polar code; and output the polar code; wherein polar codes generated by encoding data bits using an information bit index set obtained from the common bit index set have a same code length.
 7. The apparatus according to claim 6, wherein the common bit index set is a union of information bit index sets corresponding to all of polar code generated by encoding data bits using an information bit index set obtained from the common bit index set.
 8. The apparatus according to claim 6, wherein all of polar code generated by encoding data bits using an information bit index set obtained from the common bit index set corresponding to a group of polar codes the group of polar codes has different code rates.
 9. The apparatus according to claim 6, wherein the group of polar codes is one of m groups of polar codes, and wherein there is a recurrence relation among common bit index sets corresponding respectively to m groups of polar codes, wherein m is greater than or equal to
 2. 10. The apparatus according to claim 9, wherein the recurrence relation among the common bit index sets corresponding respectively to the m groups of polar codes is: $\left\{ {\begin{matrix} A_{1} \\ {A_{i} = {A_{i - 1}\bigcup{\delta \; A_{i}}}} \end{matrix},} \right.$ wherein A_(i) is a common bit index set corresponding to an i-th group of polar codes, and δA_(i) is a difference set between A_(i) and A_(i−1). 